Atlantic hurricanes: Irma and Maria

Atlantic hurricanes: Irma and Maria

On Tuesday 5th September, Hurricane Irma developed into one of the Atlantic’s most powerful storms. The category 5 hurricane - highest category storm on the Saffir-Simpson scale (a commonly used scale that attempts to measure potential property damage from storm winds) - had wind speeds around 185 mph, matching those of Wilma in 2005 which killed 87 people and cost billions of dollars in damage. As it moved through the Caribbean and towards southern Florida, Irma sustained winds of 185 mph for 37 hrs, making it the longest and most intense tropical cyclone on record.

It almost completely destroyed Barbuda as 185 mph winds, pummelled 10 Caribbean islands and US territories - including St Martin, the British Virgin Islands, Haiti, Cuba and the British territory of Turks and Caicos - before hitting Miami and tracking up the west coast of Florida. Dangerous flooding occurred along stretches of coast and 3.4 million homes were left without power. Irma killed at least 28 people, left many injured and caused widespread damage.

Less than two weeks later, the Caribbean island of Dominica was devastated by Hurricane Maria, which made landfall overnight on 18th September.

Prior to making landfall on Dominica, the storm strengthened from a category 1 to a category 5 in less than a day, with sustained winds topping 175 mph. After briefly being downgraded to a category 4 storm, it returned to a category 5 hurricane briefly, then hit Puerto Rico as a category 4 - the first hurricane of its strength to do so since 1932 - with high winds up to 155 mph and life-threatening flooding.

Some of the areas hit by Maria were subsequently affected by Hurricane Irma.

Overall, the 2017 hurricane season saw an unprecedented number of hurricanes, with 10 consecutive tropical storms reaching hurricane status. This has not been seen before since the start of the satellite era!

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